The long-term aging processes of cementless building units based on oil shale binder in water, moist and ambient air conditions were studied. The composition and the microstructure of the cured binder were also examined. An initial increase up to 3 months and then a reduction in strength of specimens with OSFA binder were noticed in ambient air. The disintegration of the hardened system was related to the transformation of ettringite - one of the most important crystal phases of cured binder. The investigation demonstrated a positive effect on the stability of the material when it was exposed to ambient air, if low-calcium coal fly ash was included in its composition.
- Aging process
- Cementless building unit
- Water, moist and ambient air conditions